Elastomeric terionomer blends

ABSTRACT

Elastomeric terionomer blends composed of (1) a copolymer of chloroprene with an α,β-unsaturated carboxylic acid, (2) a copolymer of ethylene with an α,β-unsaturated carboxylic acid, and (3) a terpolymer of ethylene with a vinyl ester of a lower saturated carboxylic acid or with a lower alkyl acrylate or methacrylate and with an α,β-unsaturated carboxylic acid, which blends are neutralized with metal ions to a degree of at least 10%, are easily processable in conventional rubber-processing equipment, can be extruded and injection-molded, and have very good physical properties and low flammability.

BACKGROUND OF THE INVENTION

This invention relates to certain thermoplastic elastomer compositionscomprising three different types of polymeric materials, suchcompositions being characterized by very good processability, hightensile strength, good oil and ozone resistance, and low flammability.

It is well known to blend polymeric materials to products havingdesirable properties. In order to achieve good blending to a homogeneousproduct, it is necessary to select starting materials that arecompatible with one another, that is, can be dispersed in one anotherwithout separating into distinct phases. Such homogeneous blends usuallycan be processed in ordinary equipment as easily as their individualcomponents. However, in rare cases, polymeric materials that can bereadily processed by themselves and that are compatible with one anotherdo not form blends that can be processed as readily.

For example, a copolymer of chloroprene with an α,β-unsaturatedcarboxylic acid such as methacrylic acid has excellent elasticity,tensile strength, and light and ozone resistance. Copolymers of ethylenewith α,β-unsaturated carboxylic acids can be crosslinked with certainmetal ions to tough resins. Each of these can be fabricated inconventional extruding or injection-molding equipment. However, whenthey are blended with each other, the resulting blend, althoughhomogeneous, is not readily processable and cannot be extruded orinjection-molded.

It is, therefore, desirable to provide readily processable blends ofcopolymers of chloroprene with α,β-unsaturated carboxylic acids withcopolymers of ethylene with α,β-unsaturated carboxylic acids.

SUMMARY OF THE INVENTION

According to this invention, there is now provided an elastomeric blendconsisting essentially of about:

(1) 20-80 weight percent of a copolymer of chloroprene with anα,β-unsaturated C₃ -C₁₀ carboxylic acid,

(2) 10-50 weight percent of a copolymer of ethylene with anα,β-unsaturated C₃ -C₁₀ carboxylic acid, and

(3) 10-50 weight percent of a terpolymer of ethylene with a vinyl esterof a C₁ -C₆ saturated aliphatic, monocarboxylic acid or a C₁₋₄ alkylacrylate or methacrylate and with an α,β-unsaturated C₃₋₁₀ carboxylicacid in respective weight proportions of (20-94.5):(5-65):(0.5-15);

with the provisos that: (a) the sum of all the above percentages of (1),(2), and (3) is 100%; and (b) the pendant carboxylic groups of thepolymer blend are neutralized with metal ions to a degree of at least10%.

DETAILED DESCRIPTION OF THE INVENTION

All the three types of polymers which form the blends of the presentinvention can be made by addition polymerization of the appropriatemonomers according to methods generally known to the art. Thus,copolymers of chloroprene with α,β-unsaturated carboxylic acids can bemade following the teachings of U.S. Pat. Nos. 2,066,331 to Carothersand 2,356,091 to Roedel. These copolymers (hereafter, occasionalllycalled copolymers of the first type) contain, in addition tochloroprene, a mono- or dicarboxylic acid comonomer such as, forexample, acrylic, methacrylic, ethacrylic, itaconic, maleic, or fumaricacid; or a monoester of a dicarboxylic acid, for example, methylhydrogen fumarate, ethyl hydrogen maleate, methyl hydrogen maleate ormethyl hydrogen itaconate. The preferred carboxylic comonomer ismethacrylic acid, and the preferred proportion of the carboxyliccomonomer is about 0.5-15 weight percent of the copolymer.

The copolymers of the second type (copolymers of ethylene with anα,β-unsaturated carboxylic acid) contain the same type of carboxyliccomonomers as the copolymers of the first type, and the preferredproportions of such comonomers are the same. Copolymers of the secondtype suitable in the compositions of the present invention are describedin U.S. Pat. No. 3,437,718 to Rees. When the proportion of the copolymerof the second type in the blend is within the range recited in theSummary of the Invention, the final blend has a practically low meltviscosity at normal processing temperatures of about 120°-170° C. andgood tensile properties.

The third type of copolymers can be made according to the teachings ofU.S. Pat. No. 3,215,678 to Adelman. Typical vinyl esters that can becopolymerized with ethylene and the α,β-unsaturated C₃₋₁₀ carboxylicacid include vinyl formate, vinyl acetate, vinyl propionate, and vinylbutyrate. Vinyl acetate is the preferred vinyl ester comonomer. Typicalcopolymerizable C₁₋₄ alkyl acrylates and methacrylates include, forexample, the isobutyl, ethyl, and preferably methyl esters of acrylicand methacrylic acids. The terpolymers of the third type contain thesame type of α,β-unsaturated carboxylic comonomers as the copolymers ofthe first and second types, and the preferred proportions of suchcomonomers again are the same. It will be clear to one skilled in theart that more than one copolymer of each type can be present in theblend, so long as the total proportion of all copolymers of each type iswithin the approximate limits indicated above in the Summary of theInvention. Furthermore, the copolymers of each type can themselvescontain more than one comonomer (for example, a copolymer containingboth acrylic and methacrylic acids). Finally, each copolymer may alsocontain a minor proportion of another ethylenically unsaturatedcomonomer, for example, an alkyl ester of an α,β-unsaturated carboxylicacid, such as methyl methacrylate, ethyl acrylate, and dibutyl maleate.All such copolymers and their blends, when used in such proportions thatthe quantitative limitations recited in the Summary of the Invention aremet, are intended to be within the scope of the invention.

As stated earlier, the blends of this invention should have theirpendant carboxylic groups neutralized to a degree of at least 10%; thatis, at least 10% of all those groups should be converted to ioniccarboxylate form, while positive charge is supplied by metal ions. Inpractice, this is best accomplished by thoroughly mixing the requisiteproportions of the copolymers of all three types and intimatelycontacting the resulting blend with a metal ion source. Suitable metalion sources are, among others, metal formates, acetates, hydroxidessoluble in water at room temperature to the extent of at least about 2%,methoxides, ethoxides, carbonates, bicarbonates, and complexes withvarious organic and inorganic molecules, especially chelating agents.Generally speaking, the same types of suitable metal ion sources as arenamed in U.S. Pat. No. 3,437,718 can be used in the compositions of theinvention. The specification of U.S. Pat. No. 3,437,718 is, therefore,incorporated herein by reference. In addition, various reactive metaloxides are also suitable ion sources, although they are usually moredifficult to disperse. Suitable metal ions are those having a valence of1 to 3, particularly those of Groups Ia, IIa, IIb, and IIIb of thePeriodic Chart of the Elements and the transition metals. The preferredmetal ion is Zn⁺².

Instead of neutralizing the polymer blend, it is possible to neutralizeone or more of the constituent, α,β-carboxylic acid comonomers prior tocopolymerization. The resultant polymers containing ionized carboxylategroups are generically known as ionomers. These ionomers can be blendedamong themselves or with free carboxylic group-containing copolymers.Additional metal ions can be added as desired to obtain any degree ofneutralization. It is preferred to achieve at least a 50% degree ofneutralization. The neutralized blend of three ionomers can be called aterionomer blend. The terionomer blend is a crosslinked material, thecrosslinking resulting from ionic attraction between the metal ions andthe carboxylic ions. These crosslinked blends are uniform andhomogeneous, even though blends of these same copolymers prior toneutralization may be inhomogeneous, nonuniform, or incompatible. Theterionomer blends have very desirable physical properties and ozoneresistance as well as low flammability. They can be made into a widevariety of useful articles by conventional methods such as, for example,extrusion or injection-molding. They also can be foamed. Typicalfabricated articles that can be made from these terionomer blendsinclude, for example, gaskets, O-rings, extruded wire and cablecoverings, shoe soles, hoses, foam insulation, etc.

The preferred terionomer blends of the present invention are thosecomprising, by weight (1) 45-65%, especially about 50%, of achloroprene/methacrylic acid copolymer wherein methacrylic acidconstitutes about 1-5% of the copolymer weight; (2) 15-30%, especiallyabout 25%, of an ethylene/methacrylic acid copolymer containing 8-15% ofmethacrylic acid; and (3) 15-30%, preferably 25%, of an ethylene/vinylacetate/methacrylic acid terpolymer wherein the proportions of vinylacetate and of methacrylic acid are, respectively, 20-30% and 1-5%; theterionomer blend being neutralized to a degree of at least 50% withzinc.

This invention is now illustrated by the following representativeexamples of certain preferred embodiments thereof, where all parts,proportions, and percentages are by weight, unless otherwise indicated.The following abbreviations are used throughout the tables.

Ac=acetate

AcAc=acetyl acetonate

E=ethylene

IBA=isobutyl acrylate

"Irganox" 1076(Ciba-Geigy)=N-octadecyl-3,5-di-t-butyl-4-hydroxyhydrocinnamamide

"Irganox" 1098(Ciba-Geigy)=N,N'-1,6-hexamethylenebis(3,5,-di-t-butyl-4-hydroxyhydrocinnamamide)

MAA=methacrylic acid

MA=methyl acrylate

St=stearate

MAME=methyl hydrogen maleate

TNMP=tris(5-norbornene-2-methyl)phosphite

VA=vinyl acetate

"Wingstay" 100 (Goodyear)=Butylated reaction product of p-cresol anddicylopentadiene

EXAMPLES 1 TO 37

Varying proportions of a chloroprene/methacrylic acid copolymercontaining either 1% or 10% of methacrylic acid, an ethylene/methacrylicacid copolymer containing 12% methacrylic acid, and an ethylene/vinylacetate/methacrylic acid terpolymer containing 28% vinyl acetate and 1%methacrylic acid were mixed together in a Brabender "Prep. Center" mixerat 120° C. Stearic acid (0.5 phr), a 5 to 1 mixture (1 phr) of "Irganox"1076 and "Irganox" 1098 antioxidants of Ciba-Geigy Corporation, and themetal cation source were subsequently added, and the terionomer blendwas formed by mixing at 120° C. and 50 rpm for 10 minutes. In Examples 1to 25, the ethylene/methacrylic acid copolymer was 38% neutralized withzinc cation prior to blending. In all Examples, except Example 36,sufficient metal cation source was added to neutralize 50% of the totalcarboxyl groups present in the polymer blend. In Example 36, the finalterionomer neutralization was only 25 %. Examples 34 and 35 are mixedmetal terionomers containing 60% zinc cation from the neutralizedethylene/methacrylic acid copolymer and 40% cation from the added metalcation source.

Stock samples were compression-molded in a preheated mold at 150° C. for7 minutes, followed by rapid cooling. Physical properties are shown inTable I. Stress/strain properties were obtained according to ASTM D395,Method B using a heat treatment of 22 hours at both 23° C. and 70° C.Hardness (durometer A) was measured at 23° C. by ASTM D2240-64T.

The following abbreviations are used for the stress/strain properties inTables I-III:

M₁₀₀ --modulus at 100% elongation (MPa)

T_(B) --tensile strength at break (MPa)

E_(B) --Elongation at break (%)

P.S.--permanent set (%)

Compression Set--(22 hrs.) (%)

                                      TABLE I                                     __________________________________________________________________________                 EXAMPLE                                                          TERIONOMER BLEND                                                                           1     2     3     4     5                                        __________________________________________________________________________    Chloroprene/MAA(phr)                                                                       59    59    60    61    50                                         % MAA       1     1     1     1     1                                       E/VA/MAA (phr)                                                                             29    25    20    15    35                                       E/MAA (phr)  12    16    20    24    15                                         %MAA Neutralized                                                                         38    38    38    38    38                                       Metal Cation Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                   Metal Source Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                           % MAA Neutralized(Tot.)                                                                    50    50    50    50    50                                       Physical Properties                                                           Shore A Hardness                                                                           72    68    79    70    83                                       Stress/Strain (23° C.)                                                   M.sub.100  3.8   3.1   4.1   3.1   3.8                                        T.sub.B    10    10.6  12.4  7.9   11.4                                       E.sub.B    400   480   480   300   520                                        P.S.       80    65    68    31    160                                      Stress/Strain (70° C.)                                                   M.sub.100  --    1.3   1.4   --    1.0                                        T.sub.B    0.8   1.4   1.6   1.1   1.5                                        E.sub.B    80    110   140   80    200                                      Compression Set                                                                 23° C.                                                                            27    --    23    --    55                                         70° C.                                                                            75    --    66    --    --                                       Melt Viscosity                                                                  (150° C., 700 s.sup.-1 )                                               (Pa.s)     970   780   1040  1000  770                                      __________________________________________________________________________                 EXAMPLE                                                          TERIONOMER BLEND                                                                           6     7     8     9                                              __________________________________________________________________________    Chloroprene/MAA(phr)                                                                       50    52    50    55                                               % MAA      1     1     1     1                                              E/VA/MAA (phr)                                                                             30    30    25    20                                             E/MAA (phr)  20    18    25    25                                               % MAA Neutralized                                                                        38    38    38    38                                             Metal Cation Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                         Metal Source Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                 % MAA Neutralized(Tot.)                                                                    50    50    50    50                                             Physical Properties                                                           Shore A Hardness                                                                           75    72    79    87                                             Stress/Strain (23° C.)                                                   M.sub.100  4.5   4.5   3.8   4.5                                              T.sub.B    14.8  11.7  11.4  12.4                                             E.sub.B    550   420   530   530                                              P.S.       145   85    109   120                                            Stress/Strain (70° C.)                                                   M.sub.100  1.5   1.4   1.3   1.4                                              T.sub.B    2.1   1.5   1.7   1.9                                              E.sub.B    200   130   200   200                                            Compression Set                                                                 23° C.                                                                            27    21    35    --                                               70° C.                                                                            --    84    80    77                                             Melt Viscosity                                                                  (150° C. 700s.sup.-1)                                                  (Pa.s)     840   860   810   970                                            __________________________________________________________________________                 EXAMPLE                                                          TERIONOMER BLEND                                                                           10    11    12    13                                             __________________________________________________________________________    Chloroprene/MAA(phr)                                                                       52    55    40    40                                               % MAA      1     1     1     1                                              E/VA/MAA (phr)                                                                             17    10    40    35                                             E/MAA (phr)  31    35    20    25                                               % MAA Neutralized                                                                        38    38    38    38                                             Metal Cation Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                         Metal Source Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                 % MAA Neutralized(Tot.)                                                                    50    50    50    50                                             Physical Properties                                                           Shore A Hardness                                                                           89    93    78    88                                             Stress/Strain (23° C.)                                                   M.sub.100  5.1   6.6   3.8   4.5                                              T.sub.B    13.1  14.5  10.0  11.0                                             E.sub.B    520   400   500   500                                              P.S.       150   111   129   200                                            Stress/Strain (70° C.)                                                   M.sub.100  1.6   1.9   1.2   1.1                                              T.sub.B    2.3   3.2   1.5   1.6                                              E.sub.B    380   360   210   360                                            Compression Set                                                                 23° C.                                                                            --    67    27    --                                               70° C.                                                                            82    --    97    92                                             Melt Viscosity                                                                  (150° C., 700 s.sup.-1)                                                (Pa.s)     920   --    740   700                                            __________________________________________________________________________                 EXAMPLE                                                          TERIONOMER BLEND                                                                           14    15    16    17                                             __________________________________________________________________________    Chloroprene/MAA(phr)                                                                       45    40    45    45                                               % MAA      1     1     1     1                                              E/VA/MAA (phr)                                                                             30    30    25    20                                             E/MAA (phr)  25    30    30    35                                               % MAA Neutralized                                                                        38    38    38    38                                             Metal Cation Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                         Metal Source Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                 % MAA Neutralized(Tot.)                                                                    50    50    50    50                                             Physical Properties                                                           Shore A Hardness                                                                           81    85    84    92                                             Stress/Strain (23° C.)                                                   M.sub.100  4.1   5.2   4.8   6.5                                              T.sub.B    12.0  12.8  12.4  13.8                                             E.sub.B    520   500   490   500                                              P.S.       145   155   135   185                                            Stress/Strain (70° C.)                                                   M.sub.100  1.3   1.5   1.5   1.9                                              T.sub.B    2.0   2.1   2.2   3.0                                              E.sub.B    310   325   310   480                                            Compression Set                                                                 23° C.                                                                            30    39    32    --                                               70° C.                                                                            92    95    91    90                                             Melt Viscosity                                                                  (150° C., 700 s.sup.-1)                                                (Pa.s)     790   830   820   820                                            __________________________________________________________________________                 EXAMPLE                                                          TERIONOMER BLEND                                                                           18    19    20    21                                             __________________________________________________________________________    Chloroprene/MAA(phr)                                                                       40    43    37    36.5                                             % MAA      1     1     1     1                                              E/VA/MAA (phr)                                                                             20    14    28    27                                             E/MAA (phr)  40    43    35    36.5                                             % MAA Neutralized                                                                        38    38    38    38                                             Metal Cation Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                         Metal Source Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                 % MAA Neutralized(Tot.)                                                                    50    50    50    50                                             Physical Properties                                                           Shore A Hardness                                                                           88    85    87    84                                             Stress/Strain (23° C.)                                                   M.sub.100  6.2   4.8   5.9   6.3                                              T.sub.B    14.5  13.1  13.8  16.6                                             E.sub.B    480   510   490   520                                              P.S.       168   180   173   250                                            Stress/Strain (70° C.)                                                   M.sub.100  2.0   1.7   1.9   1.9                                              T.sub.B    3.0   2.5   3.1   2.1                                              E.sub.B    360   300   460   200                                            Compression Set                                                                 23° C.                                                                            40    --    38    46                                               70° C.                                                                            98    --    --    95                                             Melt Viscosity                                                                  (150° C., 700 s.sup.-1)                                                (Pa.s)     840   840   --    780                                            __________________________________________________________________________                 EXAMPLE                                                          TERIONOMER BLEND                                                                           22    23    24    25                                             __________________________________________________________________________    Chloroprene/MAA(phr)                                                                       35    30    30    35                                               % MAA      1     1     1     1                                              E/VA/MAA (phr)                                                                             20    35    30    20                                             E/MAA (phr)  45    35    40    45                                               % MAA Neutralized                                                                        38    38    38    38                                             Metal Cation Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                         Metal Source Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                 % MAA Neutralized(Tot.)                                                                    50    50    50    50                                             Physical Properties                                                           Shore A Hardness                                                                           95    92    89    94                                             Stress/Strain (23° C.)                                                   M.sub.100  8.3   6.6   6.3   6.9                                              T.sub.B    15.5  13.4  13.6  12.8                                             E.sub.B    380   460   480   410                                              P.S.       190   240   196   220                                            Stress/Strain (70° C.)                                                   M.sub.100  2.3   1.7   1.7   1.5                                              T.sub.B    4.9   2.6   2.7   2.1                                              E.sub.B    490   360   480   310                                            Compression Set                                                                 23° C.                                                                            76    68    41    68                                               70° C.                                                                            --    --    --    --                                             Melt Viscosity                                                                  (150° C., 700 s.sup.-1)                                                (Pa.s)     --    610   740   --                                             __________________________________________________________________________                 EXAMPLE                                                          TERIONOMER BLEND                                                                           26    27    28    29                                             __________________________________________________________________________    Chloroprene/MAA(phr)                                                                       50    50    50    50                                               % MAA      1     1     1     1                                              E/VA/MAA (phr)                                                                             25    25    25    25                                             E/MAA (phr)  25    25    25    25                                               % MAA Neutralized                                                                        --    --    --    --                                             Metal Cation Zn(II)                                                                              Cr(III)                                                                             Co(II)                                                                              Fe(II)                                         Metal Source Zn(AcAc).sub.2                                                                      Cr(AcAc).sub.3                                                                      Co(AcAc).sub.2                                                                      Fe(AcAc).sub.2                                 % MAA Neutralized(Tot.)                                                                    50    50    50    50                                             Physical Properties                                                           Shore A Hardness                                                                           86    87    87    87                                             Stress/Strain (23° C.)                                                   M.sub.100  4.8   5.9   6.2   6.2                                              T.sub.B    8.3   11.0  11.7  11.4                                             E.sub.B    340   420   490   490                                              P.S.       130   155   149   149                                            Stress/Strain (70° C.)                                                   M.sub.100  1.3   1.7   1.4   1.8                                              T.sub.B    1.7   1.9   1.8   2.3                                              E.sub.B    200   160   190   210                                            Compression Set                                                                 23° C.                                                                            58    49    56    56                                               70° C.                                                                            --    --    --    --                                             Melt Viscosity                                                                  (150° C., 700 s.sup.-1)                                                (Pa.s)     820   710   680   900                                            __________________________________________________________________________                 EXAMPLE                                                          TERIONOMER BLEND                                                                             30     31      32      33                                      __________________________________________________________________________    Chloroprene/MAA(phr)                                                                         50     50      50      50                                        % MAA        1      1       1       1                                       E/VA/MAA (phr) 25     25      25      25                                      E/MAA (phr)    25     25      25      25                                        % MAA Neutralized                                                                          --     --      --      --                                      Metal Cation   Ni(II) Mn(II)  Cs(II)  Na(I)                                   Metal Source   Ni(AcAc).sub.2                                                                       Mn(AcAc).sub.2                                                                        Cs(AcAc).sub.2                                                                        NaAcAc                                  % MAA Neutralized(Tot.)                                                                      50     50      50      50                                      Physical Properties                                                           Shore A Hardness                                                                             88     88      86      90                                      Stress/Strain (23° C.)                                                   M.sub.100    5.2    5.5     4.8     5.5                                       T.sub.B      10.0   9.7     11.7    7.0                                       E.sub.B      400    420     650     260                                       P.S.         260    123     240     55                                      Stress/Strain (70° C.)                                                   M.sub.100    1.6    1.6     1.0     --                                        T.sub.B      2.1    1.7     1.3     1.4                                       E.sub.B      260    110     200     80                                      Compression Set                                                                 23° C.                                                                              68     56      49      57                                        70° C.                                                                              --     --      --      --                                      Melt Viscosity                                                                  (150° C., 700 s.sup.-1)                                                (Pa.s)       920    600     550     --                                      __________________________________________________________________________                 EXAMPLE                                                          TERIONOMER BLEND                                                                             34        35      36    37                                     __________________________________________________________________________    Chloroprene/MAA(phr)                                                                         50        50      50    50                                       % MAA        1         1       10    10                                     E/VA/MAA (phr) 25        25      25    25                                     E/MAA (phr)    25        25      25    25                                       % MAA Neutralized                                                                          38        38      --    --                                     Metal Cation   Zn(II)/Mg(II)                                                                           Zn(II)/Ca(II)                                                                         K(I)  K(I)                                   Metal Source   Mg(AcAc).sub.2                                                                          Ca(AcAc).sub.2                                                                        KOH   KOH                                    % MAA Neutralized(Tot.)                                                                      50        50      25    50                                     Physical Properties                                                           Shore A Hardness                                                                             88        88      85    86                                     Stress/Strain (23° C.)                                                   M.sub.100    5.5       5.5     4.4   4.8                                      T.sub.B      12.4      11.7    6.0   7.1                                      E.sub.B      480       480     300   330                                      P.S.         140       140     72    77                                     Stress/Strain (70° C.)                                                   M.sub.100    1.6       1.4     --    1.1                                      T.sub.B      2.3       2.1     1.0   1.1                                      E.sub.B      270       250     90    100                                    Compression Set                                                                 23° C.                                                                              61        58      --    --                                       70° C.                                                                              --        --      --    --                                     Melt Viscosity                                                                  (150° C., 700 s.sup.-1)                                                (Pa.s)       840       960     --    --                                     __________________________________________________________________________

EXAMPLES 38 TO 57

Terionomer blends were prepared by mixing in a Brabender mixer at 120°C. varying proportions of a chloroprene/methacrylic acid copolymer inwhich methacrylic acid constituted 1% of the copolymer, anethylene/methacrylic acid copolymer, optionally, partially neutralizedwith a metal cation, and an ethylene/vinyl acetate/methacrylic acidterpolymer. The polymers contained varying amounts of methacrylic acidand vinyl acetate. In some cases, isobutyl acrylate was used as acomonomer in the ethylene/methacrylic acid copolymer to interruptpolyethylene crystallinity and provide a softer, more extendableterionomer.

A 5 to 1 mixture of "Irganox" 1076/1098 antioxidant of Ciba-GeigyCorporation, magnesium oxide or stearate acid acceptor, and the metalsource were subsequently added, and the terionomer blend was formed bymixing at 120° for 7 to 10 minutes at 40 to 60 rpm, corresponding to amaximum shear rate of about 150 s⁻¹. During the course of mixing andterionomer formation, stock temperature in the mixing chamber rose 10°to 15° C. The terionomer was subsequently unloaded and injection-moldedinto slabs for property determination.

Injection-molded slabs (51 mm×127 mm×1.9 mm) were prepared in a NewburyRam machine. Barrel and nozzle temperatures were 160° to 170° C., andram pressures ranged from 0.05 to 82.7 MPa, depending on terionomerviscosity.

Oil volume swell was determined by ASTM D471 using ASTM No. 1 aliphaticoil and ASTM No. 3 aromatic oil (seven days immersion at 23° C. and 70°C.). Resistance to aliphatic oil was much better than that to aromaticoil and volume swell was typically 5 to 10 times greater at 70° C. thanat 23° C. The compositions and physical properties of the terionomersare given in Table II.

                                      TABLE II                                    __________________________________________________________________________                  EXAMPLE                                                          TERIONOMER BLEND                                                                           38       39   40   41                                           __________________________________________________________________________    Chloroprene/MAA(phr)                                                                        25       45   45   45                                           E/VA/MAA (phr)                                                                              35       15   15   8                                              %VA         28       28   28   28                                             %MAA        1        1    1    1                                            E/MAA (phr)   40       40   40   47                                             % MAA       10       10   10   10                                             % IBA       --       --   10   10                                             % MAA Neutralized                                                                         --       --   73   73                                           Metal Cation  Zn(II)/Al(III)                                                                         Zn(II)                                                                             Zn(II)                                                                             Zn(II)                                       Metal Source  ZnO/Al(AcAc).sub.3                                                                     ZnO  ZnO  ZnO                                          % MAA Neutralized(Tot.).                                                                    100      75   100  100                                          Acid Acceptor (phr)                                                                         --       --   --   --                                           "Irganox" 1076/1098                                                             Antioxidant (phr)                                                                         2.0/0.4  4.0/0.8                                                                            4.0/0.8                                                                            4.0/0.8                                      Physical Properties                                                           Stress/Strain (23° C.)                                                   M.sub.100   9.0      --   --   --                                             T.sub.B     10.7     18.2 17.2 18.1                                           E.sub.B     140      60   65   65                                             P.S.        23       5    4    4                                            Stress/Strain (70° C.)                                                   M.sub.100   --       --   --   --                                             T.sub.B     2.2      4.7  5.3  6.3                                            E.sub.B     70       40   70   100                                          Oil Swell (.increment.V/V.sub.1, %)                                           (7 days immersion)                                                            23° C. ASTM No. 1 Oil                                                                1.4      0.8  1.3  1.0                                              ASTM No. 3 Oil                                                                          16.4     10.4 16.9 14.0                                         70° C. ASTM No. 1 Oil                                                                32.7     13.4 27.6 21.8                                             ASTM No. 3 Oil                                                                          97.4     93.9 174.6                                                                              180.7                                        __________________________________________________________________________                 EXAMPLE                                                          TERIONOMER BLEND                                                                           42   43      44   45                                             __________________________________________________________________________    Chloroprene/MAA(phr)                                                                       45   50      50   60                                             E/VA/MAA (phr)                                                                             15   17      17   30                                               % VA       28   28      28   28                                               % MAA      1    1       1    1                                              E/MAA (phr)  40   33      33   10                                               % MMA      10   12      10   10                                               % IBA      10   --      10   10                                               % MAA Neutralized                                                                        73   38      73   73                                             Metal Cation Na(I)                                                                              Zn(II)/Ca(II)                                                                         Zn(II)                                                                             Zn(II)                                         Metal Source NaAcAc                                                                             ZnO/CaSt.sub.2                                                                        ZnO  Zn(AcAc).sub.2                                 % MAA Neutralized(Tot.)                                                                    75   100     100  75                                             Acid Acceptor (phr)                                                                        --   3.8 MgO 3.8 MgO                                                                            3.8 MgO                                        "Irganox" 1076/1098                                                             Antioxidant (phr)                                                                        4.0/0.8                                                                            8.8/1.8 8.8/1.8                                                                            2.0/0.4                                        Physical Properties                                                           Stress/Strain (23° C.)                                                   M.sub.100  --   --      --   9.0                                              T.sub.B    12.9 19.0    16.6 11.8                                             E.sub.B    115  30      85   140                                              P.S.       8    5       5    7                                              Stress/Strain (70° C.)                                                   M.sub.100  --   --      --   --                                               T.sub.B    2.8  8.3     7.4  3.2                                              E.sub.B    40   90      95   90                                             Oil Swell (.increment.V/V.sub.1, %)                                           (7 days immersion)                                                            23° C. ASTM No. 1 Oil                                                               1.1  0.9     0.9  2.4                                                ASTM No. 3 Oil                                                                         17.2 12.5    16.5 31.1                                           70° C. ASTM No. 1 Oil                                                               21.9 13.8    24.6 45.2                                               ASTM No. 3 Oil                                                                         156.1                                                                              96.8    156.3                                                                              108.2                                          __________________________________________________________________________                 EXAMPLE                                                          TERIONOMER BLEND                                                                           46    47    48    49                                             __________________________________________________________________________    Chloroprene/MAA(phr)                                                                       25    45    60    50                                             E/VA/MAA (phr)                                                                             35    15    30    25                                               % VA       28    28    28    28                                               % MAA      1     1     1     1                                              E/MAA (phr)  40    40    10    25                                               % MAA      10    10    10    12                                               % IBA      10    10    10    --                                               %MAA Neutralized                                                                         73    73    73    38                                             Metal Cation Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                         Metal Source Zn(AcAc).sub.2                                                                      Zn(AcAc).sub.2                                                                      ZnO   Zn(AcAc).sub.2                                 % MAA Neutralized (Tot.)                                                                   75    75    100   50                                             Acid Acceptor (phr)                                                                        0.6 MgO                                                                             6.7MgSI.sub.2                                                                       6.7 MgSt.sub.2                                                                      6.7 MgSt.sub.2                                 "Irganox" 1076/1098                                                             Antioxident (phr)                                                                        2.0/0.4                                                                             2.0/0.4                                                                             2.0/0.4                                                                             2.0/0.4                                        Physical Properties                                                           Stress/Strain (23° C.)                                                   M.sub.100  --    13.4  6.3   --                                               T.sub.B    16.1  15.6  7.2   15.1                                             E.sub.B    80    160   135   75                                               P.S.       7     20    60    5                                              Stress/Strain (70° C.)                                                   M.sub.100  --    --    --    --                                               T.sub.B    4.2   9.4   2.1   4.5                                              E.sub.B    100   165   100   45                                             Oil Swell (.increment.V/V.sub.1, %)                                           (7 days immersion)                                                            23° C. ASTM No. 1 Oil                                                               1.5   1.1   2.1   0.3                                                ASTM No. 3 Oil                                                                         19.4  17.4  30.1  10.9                                           70° C. ASTM No. 1 Oil                                                               48.8  27.6  33.3  38.6                                               ASTM No. 3 Oil                                                                         131.1 171.6 94.8  142.6                                          __________________________________________________________________________                 EXAMPLE                                                          TERIONOMER BLEND                                                                           50    51    52    53                                             __________________________________________________________________________    Chloroprene/MAA(phr)                                                                       50    50    50    50                                             E/VA/MAA (phr)                                                                             25    25    25    25                                               % VA       28    28    28    25                                               %MAA       1     1     1     1                                              E/MAA (phr)  25    25    25    25                                               % MAA      10    10    10    12                                               % IBA      10    --    10    --                                               % MAA Neutralized                                                                        73    50    73    38                                             Metal Cation Zn(II)                                                                              Na(I) Na(I) Zn(II)                                         Metal Source ZnO   NaAc  NaAc  Zn(AcAc).sub.2                                 % MAA Neutralized(Tot.)                                                                    55    50    50    50                                             Acid Acceptor (phr)                                                                        6.7 MgSt.sub.2                                                                      6.7 MgSt.sub.2                                                                      6.7 MgSt.sub.2                                                                      6.7 MgSt.sub.2                                 "Irganox" 1076/1098                                                             Antioxidant (phr)                                                                        2.0/0.4                                                                             2.0/0.4                                                                             2.0/0.4                                                                             2.0/0.4                                        Physical Properties                                                           Stress/Strain (23° C.)                                                   M.sub.100  7.8   --    10.8  --                                               T.sub.B    10.8  11.6  12.0  9.1                                              E.sub.B    200   100   170   80                                               P.S.       30    10    20    8                                              Stress/Strain (70° C.)                                                   M.sub.100  --    --    --    --                                               T.sub.B    2.5   4.1   2.9   2.1                                              E.sub.B    105   50    80    60                                             Oil Swell (.increment.V/V.sub.1, %)                                           (7 days immersion)                                                            23° C. ASTM No. 1 Oil                                                               0.9   0.7   0.7   0.6                                                ASTM No. 3 Oil                                                                         13.2  11.9  13.9  16.2                                           70° C. ASTM No. 1 Oil                                                               44.7  35.7  35.3  78.1                                               ASTM No. 3 Oil                                                                         >200  133.1 >200  161.2                                          __________________________________________________________________________                 EXAMPLE                                                          TERIONOMER BLEND                                                                           54    55    56    57                                             __________________________________________________________________________    Chloroprene/MAA(phr)                                                                       50    50    50    50                                             E/VA/MAA (phr)                                                                             25    25    25    25                                               % VA       25    25    25    28                                               % MAA      1     1     1     5                                              E/MAA (phr)  25    25    25    25                                               % MAA      10    10    10    10                                               % IBA      10    --    10    10                                               % MAA Neutralized                                                                        73    50    73    73                                             Metal Cation Zn(II)                                                                              Na(I) Na(I) Zn(II)                                         Metal Source ZnO   NaAc  NaAc  ZnO                                            % MAA Neutralized(Tot.)                                                                    55    50    50    42                                             Acid Acceptor (phr)                                                                        6.7 MgSt.sub.2                                                                      6.7 MgSt.sub.2                                                                      6.7 MgSt.sub.2                                                                      6.7 MgSt.sub.2                                 "Irganox" 1076/1098                                                             Antioxidant (phr)                                                                        2.0/0.4                                                                             2.0/0.4                                                                             2.0/0.4                                                                             2.0/0.4                                        Physical Properties                                                           Stress/Strain (23° C.)                                                   M.sub.100  6.3   --    5.7   4.5                                              T.sub.B    6.7   6.2   6.1   7.8                                              E.sub.B    120   100   160   310                                              P.S.       15    15    25    70                                             Stress/Strain (70° C.)                                                    M.sub.100 --    --    --    1.3                                              T.sub.B    1.2   1.2   0.9   1.6                                              E.sub.B    95    85    140   225                                            Oil Swell (.increment.V/V.sub.1, %)                                           (7 days immersion)                                                            23° C. ASTM No. 1 Oil                                                               1.4   1.3   1.4   0.0                                                ASTM No. 3 Oil                                                                         24.4  21.0  25.9  8.5                                            70° C. ASTM No. 1 Oil                                                               44.4  29.1  33.6  18.8                                               ASTM No. 3 Oil                                                                         >200  133   136.5 180                                            __________________________________________________________________________

EXAMPLES 58 TO 82

Terionomer blends were prepared and injection molded by the proceduredescribed for Examples 38 to 57. From 3.5 to 11 phr of Sb₂ O₃ wasincluded in the blends as flame retardant. In Examples 77 to 81, 1.4 phrof "Wingstay" 100 of Goodyear Rubber & Tire Company oftris(5-norbornene-2-methyl) phosphite was added to provide ozoneresistance.

Static ozone resistance was measured according to ASTM D518-61 byexposing stock samples to ozone in a test chamber at 40° C. using anozone concentration of 3 ppm for 360 hours. Samples (25 mm×150 mm×1.9 mmthick) were mounted on a varnished wooden rack and subjected to atensile strain of 40%. Examples 77 to 81 showed no visible crackingafter 360 hours of ozone exposure. In contrast, a commercially availablestyrene/butadiene/styrene (SBS) triblock copolymer containing 1.3 phr"Wingstay" 100 and having comparable mechanical properties failed afteronly a few hours of ozone exposure, as can be seen in Example 82(comparative).

Flammability was measured in an ASTM D1692-67T horizontal burn test byapplying a Bunsen flame to a 1.27 cm wide and 1.9 mm thick stock samplefor 15 seconds. Burn time was measured from the time of flameapplication. All samples burned without dripping and self-extinguishedgenerally within a half minute. The terionomers were highly resistant toburning even when only 3.5 phr Sb₂ O₃ was used. In contrast, the entirelength of the SBS copolymer test strip burned in about 10 minutes,despite the presence of 6.6 phr of Sb₂ O₃. Compositions and physicalproperties of the terionomers are given in Table III.

                                      TABLE III                                   __________________________________________________________________________                    EXAMPLE                                                       TERIONOMER BLEND                                                                              58    59    60   61                                           __________________________________________________________________________    Chloroprene/MAA (phr)                                                                         50    50    50   60                                             % MAA         1     1     1    1                                            E/VA/MAA (phr)  25    25    25   10                                             % VA          28    28    28   28                                             % MAA         1     5     1    5                                            E/MAA (phr)     25    25    25   30                                             % MAA         10    10    12   10                                             % IBA         10    10    --   10                                             % MAA Neutralized                                                                           73    73    --   73                                           Metal Cation    Na(I) Na(I) Fe(II)                                                                             Zn(II)                                       Metal Source    NaAc  NaAc  FeSt.sub.2                                                                         ZnO                                          % MAA Neutralized (Tot.)                                                                      100   74    36   89                                           MgSt.sub.2 Acid Acceptor                                                                      1.2   1.2   1.2  1.2                                            (phr)                                                                       "Irganox" 1076/1098                                                                           0.8/0.2                                                                             0.8/0.2                                                                             0.8/0.2                                                                            0.8/0.2                                        Antioxidant (phr)                                                           Sb.sub.2 O.sub.3 (phr)                                                                        11    11    11   11                                           Stearic Acid (phr)                                                                            --    --    --   --                                           "Wingstay"100 (phr)                                                                           --    --    --   --                                           TNMP (phr)      --    --    --   --                                           Physical Properties                                                           Stress/Strain (23° C.)                                                   M.sub.100     3.1   3.0   4.2  3.6                                            T.sub.B       8.2   8.1   7.1  11.9                                           E.sub.B       530   580   350  470                                            P.S.          95    90    65   55                                           Flammability                                                                    Burn Time (sec.)                                                                            26    24    34   23                                             Drip          No    No    No   No                                             Char          Yes   Yes   Yes  Yes                                            Self-Extinguishing                                                                          Yes   Yes   Yes  Yes                                            Burn Length (cm.)                                                                           1.91  0.64  1.91 0.33                                         Static Ozone Resistance                                                       (40% elongation, 3ppm                                                                         --    --    --   --                                           Ozone, 360 hrs., 40° C.)                                               __________________________________________________________________________                    EXAMPLE                                                       TERIONOMER BLEND                                                                              62    63    64   65                                           __________________________________________________________________________    Chloroprene/MAA (phr)                                                                         60    50    50   50                                             % MAA         1     1     1    1                                            E/VA/MAA (phr)  30    25    17   25                                             % VA          28    28    28   28                                             % MAA         5     5     1    1                                            E/MAA (phr)     10    25    33   25                                             % MAA         10    10    10   12                                             % IBA         10    10    10   --                                             % MAA Neutralized                                                                           73    73    73   38                                           Metal Cation    Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                                                             Zn(II)                                       Metal Source    ZnO   ZnO   ZnO  Zn(AcAc).sub.2                               % MAA Neutralized (Tot.)                                                                      59    77    100  50                                           MgSt.sub.2  Acid Acceptor                                                                     1.2   1.2   1.2  1.6                                            (phr)                                                                       "Irganox" 1076/1098                                                                           0.8/0.2                                                                             0.8/0.2                                                                             0.8/0.2                                                                            0.8/0.2                                        Antioxidant (phr)                                                           Sb.sub.2 O.sub.3 (phr)                                                                        11    11    11   6.6                                          Stearic Acid (phr)                                                                            --    --    1.1  --                                           "Wingstay"100 (phr)                                                                           --    --    --   --                                           TNMP (phr)      --    --    --   --                                            Physical Properties                                                          Stress/Strain (23° C.)                                                   M.sub.100     2.6   3.2   4.9  4.1                                            T.sub.B       8.4   9.0   9.9  9.1                                            E.sub.B       590   495   395  440                                            P.S.          60    70    80   100                                          Flammability                                                                    Burn Time (sec.)                                                                            19    21    40   53                                             Drip          No    No    No   No                                             Char          Yes   Yes   Yes  Yes                                            Self-Extinguishing                                                                          Yes   Yes   Yes  Yes                                            Burn Length (cm.)                                                                           0.33  0.33  0.64 1.27                                         Static Ozone Resistance                                                       (40% elongation, 3ppm                                                                         --    --    --   --                                           Ozone, 360 hrs., 40° C.)                                               __________________________________________________________________________                    EXAMPLE                                                       TERIONOMER BLEND                                                                              66    67    68   69                                           __________________________________________________________________________    Chloroprene/MAA (phr)                                                                         50    50    50   50                                             % MAA         1     1     1    1                                            E/VA/MAA (phr)  25    25    25   25                                             % VA          28    28    28   25                                             % MAA         1     1     1    1                                            E/MAA (phr)     25    25    25   25                                             % MAA         10    10    10   2                                              % IBA         10    --    10   --                                             % MAA Neutralized                                                                           73    50    73   38                                           Metal Cation    Zn(II)                                                                              Na(I) Na(I)                                                                              Zn(II)                                       Metal Source    ZnO   NaAc  NaAc Zn(AcAc).sub.2                               % MAA Neutralized (Tot.)                                                                      55    50    50   50                                           MgSt.sub.2 Acid Acceptor                                                                      1.6   1.6   1.6  1.6                                            (phr)                                                                       "Irganox" 1076/1098                                                                           0.8/0.2                                                                             0.8/0.2                                                                             0.8/0.2                                                                            0.8/0.2                                        Antioxidant (phr)                                                           Sb.sub.2 O.sub.3 (phr)                                                                        6.6   6.6   6.6  6.6                                          Stearic Acid (phr)                                                                            --    --    --   --                                           "Wingstay"100 (phr)                                                                           --    --    --   --                                           TNMP (phr)      --    --    --   --                                           Physical Properties                                                           Stress/Strain (23° C.)                                                   M.sub.100     2.6   3.8   3.1  3.2                                            T.sub.B       7.9   7.8   9.7  3.2                                            E.sub.B       540   435   545  100                                            P.S.          95    135   135  10                                           Flammability                                                                    Burn Time (sec.)                                                                            25    26    28   21                                             Drip          No    No    No   No                                             Char          Yes   Yes   Yes  Yes                                            Self-Extinguishing                                                                          Yes   Yes   Yes  Yes                                            Burn Length (cm.)                                                                           0.64  0.33  0.33 0.33                                         Static Ozone Resistance                                                       (40% elongation, 3ppm                                                                         --    --    --   --                                           Ozone, 360 hrs., 40° C.)                                               __________________________________________________________________________                    EXAMPLE                                                       TERIONOMER BLEND                                                                              70    71    72   73                                           __________________________________________________________________________    Chloroprene/MAA (phr)                                                                         50    50    50   50                                             % MAA         1     1     1    1                                            E/VA/MAA (phr)  25    25    25   25                                             % VA          25    25    25   28                                             % MAA         1     1     1    1                                            E/MAA (phr)     25    25    25   25                                             % MAA         10    10    10   12                                             % IBA         10    --    10   --                                             % MAA Neutralized                                                                           73    50    73   --                                           Metal Cation    Zn(II)                                                                              Na(I) Na(I)                                                                              Mg(II)                                       Metal Source    ZnO   NaAc  NaAc Mg(AcAc).sub.2                               % MAA Neutralized (Tot.)                                                                      55    50    50   45                                           MgSt.sub.2 Acid Acceptor                                                                      1.6   1.6   1.6  1.6                                            (phr)                                                                       "Irganox" 1076/1098                                                                           0.8/0.2                                                                             0.8/0.2                                                                             0.8/0.2                                                                            0.8/0.2                                        Antioxidant (phr)                                                           Sb.sub.2 O.sub.3 (phr)                                                                        6.6   6.6   6.6  3.5                                          Stearic Acid (phr)                                                                            --    --    --   --                                           "Wingstay"100 (phr)                                                                           --    --    --   --                                           TNMP (phr)      --    --    --   --                                           Physical Properties                                                           Stress/Strain (23° C.)                                                   M.sub.100     2.3   2.5   2.7  5.1                                            T.sub.B       2.5   2.5   2.8  9.7                                            E.sub.B       160   100   190  405                                            P.S.          15    10    30   160                                          Flammability                                                                    Burn Time (sec.)                                                                            23    26    25   25                                             Drip          No    No    No   No                                             Char          Yes   Yes   Yes  Yes                                            Self-Extinguishing                                                                          Yes   Yes   Yes  Yes                                            Burn Length (cm.)                                                                           0.33  0.33  0.33 0.64                                         Static Ozone Resistance                                                       (40% elongation, 3ppm                                                                         --    --    --   --                                           Ozone, 360 hrs., 40° C.)                                               __________________________________________________________________________                    EXAMPLE                                                       TERIONOMER BLEND                                                                              74    75    76   77                                           __________________________________________________________________________    Chloroprene/MAA (phr)                                                                         50    57    60   60                                             % MAA         1     1     1    1                                            E/VA/MAA (phr)  25    29    30   10                                             % VA          28    28    28   28                                             % MAA         1     1     1    1                                            E/MAA (phr)     25    14    10   30                                             % MAA         12    12    12   10                                             % MAA         --    --    --   10                                             % MAA Neutralized                                                                           --    --    --   73                                           Metal Cation    Zn(II)                                                                              Zn(II)                                                                              Zn(II)                                                                             Na(I)                                        Metal Source    ZnO   ZnO   ZnO  NaAc                                         % MAA Neutralized (Tot.)                                                                      50    70    86   100                                          MgSt.sub.2 Acid Acceptor                                                                      1.6   1.6   1.6  1.6                                            (phr)                                                                       "Irganox" 1076/1098                                                                           0.8/0.2                                                                             0.8/0.2                                                                             0.8/0.2                                                                            0.8/0.2                                        Antioxidant (phr)                                                           Sb.sub.2 O.sub.3 (phr)                                                                        3.5   3.5   3.5  3.5                                          Stearic Acid (phr)                                                                            --    --    --   --                                           "Wingstay" 100 (phr)                                                                          --    --    --   1.4                                          TNMP (phr)      --    --    --   --                                           Physical Properties                                                           Stress/Strain (23° C.)                                                   M.sub.100     5.3   3.8   3.0  3.3                                            T.sub.B       11.5  11.1  10.7 10.9                                           E.sub.B       390   480   485  525                                            P.S.          115   90    70   80                                           Flammability                                                                    Burn Time (sec.)                                                                            24    18    17   25                                             Drip          No    No    No   No                                             Char          Yes   Yes   Yes  Yes                                            Self-Extinguishing                                                                          Yes   Yes   Yes  Yes                                            Burn Length (cm.)                                                                           0.64  0.33  0.33 0.64                                         Static Ozone Resistance                                                       (40% elongation, 3ppm                                                                         --    --    --   No                                           Ozone, 360 hrs., 40° C.)  Failure                                      __________________________________________________________________________                  EXAMPLE                                                         TERIONOMER BLEND                                                                            78   79    80  81  82                                           __________________________________________________________________________    Chloroprene/MAA (phr)                                                                       60   50    50  50                                                 % MAA       1    1     1   1   Commercial                                   E/VA/MAA (phr)                                                                              30   25    25  25  SBS                                            % VA        28   28    28  28  Copolymer                                      % MAA       1    1     1   1   (Comparison)                                 E/MAA (phr)   10   25    25  25                                                 % MAA       10   12    10  10                                                 % IBA       10   --    --  10                                                 % MAA Neutralized                                                                         73   38    50  73                                               Metal Cation  Na(I)                                                                              Zn(II)                                                                              Na(I)                                                                             Zn(II) -Metal Source                                                              NaAc Zn(AcAc).sub.2 NaAc ZnO --              % MAA Neutralized (Tot.)                                                                    100  50    50  56  --                                           MgSt.sub.2 Acid Acceptor                                                                    1.6  1.6   1.6 1.6 --                                             (phr)                                                                       "Irganox" 1076/1098                                                                         0.8/0.2                                                                            0.8/0.2                                                                             0.8/0.2                                                                           0.8/0.2                                                                           --                                             Antioxidant (phr)                                                           Sb.sub.2 O.sub.3 (phr)                                                                      3.5  3.5   3.5 3.5 6.6                                          Stearic Acid (phr)                                                                          --   --    --  --  --                                           "Wingstay" 100 (phr)                                                                        1.4  1.4   1.4 --  1.3                                          TNMP (phr)    --   --    --  1.4 --                                           Physical Properties                                                           Stress/Strain (23° C.)                                                   M.sub.100   2.3  4.4   4.1 4.6 3.6                                            T.sub.B     10.7 9.7   9.6 5.4 8.2                                            E.sub.B     600  425   480 340 520                                            P.S.        85   115   155 70  40                                           Flammability                                                                    Burn Time (sec.)                                                                          19   21    18  39  566                                            Drip        No   No    No  No  No                                             Char        Yes  Yes   Yes Yes Yes                                            Self-Extinguishing                                                                        Yes  Yes   Yes Yes No                                             Burn Length (cm.)                                                                         0.18 0.64  0.18                                                                              0.33                                                                              15.2                                         Static Ozone                                                                  Resistance (40%                                                               elongation, 3ppm                                                              Ozone, 360 hrs.,                                                                            No   No    No  No  Failed                                       40° C.)                                                                              Failure                                                                            Failure                                                                             Failure                                                                           Failure                                                                           2-8 hours                                    __________________________________________________________________________

EXAMPLES 83 TO 84

Terionomer blends were prepared according to the procedure used forExamples 38 to 57 by mixing 50% of (1) a chloroprene/methyacrylic acidcopolymer containing 1% of methacrylic acid based on the weight of thecopolymer, (2) 25% of an ethylene/methyl acrylate/methyl hydrogenmaleate copolymer containing 54% of methyl acrylate and 4% of methylhydrogen maleate based on the weight of the copolymer and (3) 25% of anethylene/methacrylic acid/isobutyl acrylate copolymer containing 10% ofmethacrylic acid and 10% of isobutyl acrylate. In Example 83, 36% ofcarboxyl groups of the ethylene/methacrylic acid/isobutyl acrylatecopolymer were neutralized prior to blending with sodium ions and, inExample 84, 73% of the carboxyl groups were similarly neutralized withzinc cations. In Example 83, sufficient sodium acetate was then added toneutralize 50% of the total carboxyl groups present in the polymerblend. In Example 84, no additional metal cation source was added, sothat 56% of the carboxyl groups in the polymer blend were neutralizedwith zinc cations.

Blend samples were injection-molded for property determination asdescribed in Examples 38 to 57. Stress-strain properties andflammability data are given in Table IV.

                  TABLE IV                                                        ______________________________________                                                              Example                                                                         83       84                                           ______________________________________                                        Terionomer Blend                                                              Chloroprene/MAA (phr)   50       50                                           E/MA/MAME (phr)         25       25                                           E/MAA/IBA (phr)         25       25                                             %MAA Neutralized      36       73                                           Metal Cation            Na(I)    Zn(II)                                       Metal Source            NaAc     ZnO                                          % MAA Neutralized (total)                                                                             50       56                                           MgSt.sub.2 Acid Acceptor (phr)                                                                        1.6      1.6                                          "Irganox" 1076/1098 Antioxidant (phr)                                                                 0.8/0.2  0.8/0.2                                      Sb.sub.2 O.sub.3 (phr)  3.5      3.5                                          Physical Properties                                                           Stress/Strain (23° C.)                                                   M.sub.100             --       2.2                                            T.sub.B               12.6     6.3                                            E.sub.B               100      620                                            P.S.                  18       110                                          Flammability                                                                    Burn Time (sec)       34       21                                             Drip                  No       No                                             Char                  Yes      Yes                                            Self-extinguishing    Yes      Yes                                            Burn length (cm.)     0.64     0.33                                         ______________________________________                                    

I claim:
 1. An elastomeric blend consisting essentially of about:(1)20-80 weight percent of a copolymer of chloroprene with anα,β-unsaturated C₃ -C₁₀ carboxylic acid, (2) 10-50 weight percent of acopolymer of ethylene with an α,β-unsaturated C₃ -C₁₀ carboxylic acid,and (3) 10-50 weight percent of a terpolymer of ethylene with a vinylester of a C₁ -C₆ saturated aliphatic, monocarboxylic acid or a C₁ -4alkyl acrylate or methacrylate and with an α,β-unsaturated C₃₋₁₀carboxylic acid in respective weight proportions of(20-94.5):(5-65):(0.5-15); with the provisos that: (a) the sum of allthe above percentages of (1), (2), and (3) is 100%; and (b) the pendantcarboxylic groups of the polymer blend are neutralized with metal ionsto a degree of at least 10%.
 2. A blend of claim 1 wherein the pendantcarboxylic groups are neutralized with metal ions to a degree of atleast 50%.
 3. A blend of claim 2 wherein component (1) is a copolymer ofchloroprene with methacrylic acid wherein methacrylic acid constitutesabout 1-5% of the copolymer weight; component (2) is a copolymer ofethylene with methacrylic acid wherein methacrylic acid constitutesabout 8-15% of the copolymer weight; and component (3) is a terpolymerof ethylene with vinyl acetate and methacrylic acid, the respectiveweight proportions of the last-named two comonomers being about 20-30%and 1-5%.
 4. A blend of claim 3 wherein component (1) is present in aweight proportion of about 45-65%; component (2) is present in a weightproportion of about 15-30%; and component (3) is present in a weightproportion of about 15-30%.
 5. A blend of claim 1 wherein the pendantcarboxylic groups of at least one copolymer are derived from at leasttwo different α,β-unsaturated acid comonomers.
 6. A blend of claim 1wherein at least one copolymer contains a small amount of at least oneadditional ethylenically unsaturated comonomer.
 7. A blend of claim 1wherein the metal ion in Zn⁺².
 8. A blend of claim 1 wherein the metalion is Na⁺¹.